JPS6336303B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel masking method in two-tone painting.

2. Description of the Related Art In painting automobile bodies, so-called two-tone painting, in which the body is painted in two or more colors, is used as a means to improve aesthetic appearance.

As shown in the cross-sectional view in Figure 1, this two-tone painting is usually done by applying the first color of paint 2 on top of the body 1 (electrodeposition paint, intermediate coat, etc.).
This is done by partially applying the second color coating 3 on top of the first color coating 2, but the first color coating 2 and the second color coating 3 are
Masking tape is used to form the border. That is, as shown in FIG. 2, a masking tape 4 is pasted on the part that should be the boundary between the first color paint 2 and the second color paint 3, and a heat-resistant adhesive tape 6 is pasted thereon. The edges of the masking paper 5 are partially overlapped and fixed, and then the second color coating 3 is applied, and then the masking tape 4 is peeled off together with the masking paper 5 and the heat-resistant adhesive tape 6, thereby forming the first masking paper 5. The boundary between the color coating 2 and the second color coating 3 is clearly formed.

In the conventional method, a tape substrate 4a as shown in FIG. 3 with an adhesive layer 4b formed on the entire surface of one side is used as the masking tape 4, but such masking tape is coated with a first color. When the masking tape 4 is pressed onto the masking tape 4, the adhesive protrudes from both sides of the masking tape 4 as shown in Fig. 4. When the second color 3 is applied in that state and the masking tape 4 is peeled off, the adhesive is shown in Fig. 5. As shown, the adhesive in the protruding portion is not removed together with the masking tape 4 and remains as a line 7, resulting in a poor appearance. When the first color of the paint 2 is black, the streaks 7 are particularly noticeable. For this reason, in the conventional method, it is necessary to further remove the streaks 7 after peeling off the masking tape 4, resulting in an increase in the number of finishing steps. In addition, when using the conventional masking tape 4, it protrudes toward the boundary between the first color coating 2 and the second color coating 3, as shown in Figure 4, but this tape extends beyond the boundary between both coatings. Therefore, it is not noticeable, and most of it is covered with the second color paint 3, so it does not pose any particular problem.

As shown in Figure 6, the two-tone painting method involves partially painting the body 1 with the first color 8.
There is a method of applying a second color of paint 9 to the rest of the body 1 so as to partially overlap with this, but even with this method, as long as the conventional masking tape 4 is used, there is the problem of streaks. be.

However, as a result of intensive study to develop a masking method that can solve the problem of streaks that occur when using conventional masking tapes coated with adhesive on the entire surface, the present inventors have developed the novel masking method of the present invention. Reached.

That is, the present invention is a masking tape used to form a boundary between two different paint colors during two-tone painting, and which does not have an adhesive layer on the opposite end of the edge corresponding to the boundary line between the two paints. The present invention relates to a masking method in two-tone painting, which is characterized by using masking tape.

Next, the method of the present invention will be explained with reference to the drawings.

FIG. 7 is a cross-sectional view showing one embodiment of the masking tape used in the present invention, in which the masking tape 11 has an adhesive layer 11b on a tape base material 11a, leaving one end in the longitudinal direction of the tape. It was originally formed.

FIG. 8 is a sectional view showing an example of a masking method using the masking tape 11, in which a first color coating 2 is applied to a body 1 (on which electrodeposition coating, intermediate coating, etc. have been applied), Moreover, the masking tape 11 is crimped so that the end on the side having the adhesive layer 11b coincides with the boundary between the first color coating 2 and the second color coating applied thereon. At this time, since the adhesive layer 11b is not present at the end of the masking tape 11 opposite to the edge corresponding to the boundary, there is a risk that the adhesive will protrude to the side of the masking tape 11 even by pressure bonding. do not have. After pasting the masking tape 11 in this way, the edge of the masking paper 5 with the heat-resistant adhesive tape 6 pasted thereon is partially overlapped and fixed.
After that, a second color coating 3 is applied, and then the masking tape 11 is peeled off together with the masking paper 5 and the heat-resistant adhesive tape 6, so that a clear boundary is formed between the first color coating 2 and the second color coating 3. However, since the adhesive does not protrude from the side of the masking tape 11 opposite to the border, there is no risk of the adhesive remaining after the masking tape 11 is peeled off, and the streaks as shown in FIG. 5 are avoided. No eyes remain. Note that even if the masking tape 11 is used, there is a risk that the adhesive will protrude toward the boundary between the first color coating 2 and the second color coating 3, but this is not a problem because it is not noticeable as described above. Note that if masking tape does not have an adhesive layer on the edge corresponding to the boundary line, positioning will not be possible. Therefore, the edge corresponding to the border line cannot be pasted to match the preset border line accurately), and the border line is not clear (the edge where no adhesive layer exists and the first color coating 2 The paint of the second color 3 enters into the gap between the two, but the degree of penetration is irregular, resulting in problems such as a meandering border line.

As described above, when using the masking method of the present invention, the appearance of the boundary between the first color coating 2 and the second color coating 3 is finished well because no streaks occur due to residual adhesive. , there is no need for an extra finishing step to remove streaks as in conventional masking methods.

The masking method of the present invention involves applying a first color coating 8 to a portion of the body 1 as shown in FIG. It can be similarly applied to the two-tone painting method applied to parts.

The masking tape 11 used in the present invention is not particularly limited except that the adhesive layer 11b is partially provided on the tape base material 11a so that it is not present at one end, and is made of a normal tape base material. and adhesive are both used. For example, tape base materials include polyester, kraft paper,
Polypropylene, polyvinyl chloride, cellophane, crepe paper, etc. are used as adhesives, but acrylic resin,
Synthetic rubber, natural rubber, etc. are used. The width of the portion of one end of the masking tape 11 where the adhesive layer 11b is not provided can be determined appropriately so that the adhesive does not protrude to the side when the masking tape 11 is pressure-bonded onto the first color coating. good.

As the masking paper 5 and the heat-resistant adhesive tape 6, any ordinary ones can be used.

Both regular solid color and metallic color coatings can be used for the first and second color coatings, whether they are one coat or two coats consisting of a base coat and a clear coat. good.

In the above, the case where the method of the present invention is applied to two-color two-tone painting has been explained.
It goes without saying that the method of the present invention can also be applied to coatings with three or more colors.

Furthermore, the method of the present invention is applicable not only to two-tone painting of automobile bodies, but also to electrical products, motorcycles, containers, etc.
It can also be suitably applied to two-tone painting of railway vehicles, etc.

Next, the method of the present invention will be explained with reference to Examples and Comparative Examples.

Example Two-tone painting was applied to the body of a wagon type automobile as shown in FIG. The front panel 12 was painted two-tone as shown in FIG. 1, and the side surface 13 was painted two-tone as shown in FIG.

A polybutadiene-based electrocoating paint was electrocoated to a dry film thickness of approximately 20μ on a white body that had undergone zinc phosphate chemical conversion treatment, and then baked at 170°C for 18 minutes. On top of that, I applied Surf Acer, an intermediate coating for automobiles, to a dry film thickness of about 20μ, and without letting the resulting paint film dry, I applied black solid color paint for base coat to the entire front panel of the body to a dry film thickness of 20μ. It was coated and baked at 140° C. for 18 minutes to obtain a black first color coating 14.

On the other hand, a silver metallic base coat paint containing aluminum powder and black pigment was applied to the lower side of the body to a dry film thickness of 15μ, and while the resulting paint film was not drying, clear paint was applied to the dry film thickness. It was coated to a thickness of 25μ and baked at 140°C for 18 minutes to obtain a silver metallic first color coating 15.

Next, apply a synthetic rubber adhesive to a polyester film with a width of 15 mm, leaving a width of 3 to 4 mm at one end to form an adhesive layer of 10 to 20 μm, and then apply masking tape to the front panel. The tape was crimped onto the first color coating 14 so that the edge of the tape having the adhesive layer coincided with the boundary between the first color coating and the second color coating provided thereon. At this time, the adhesive did not protrude from the end of the tape on the side without the adhesive layer. Masking was performed by partially overlapping the edge of the masking paper with the heat-resistant adhesive tape attached on top of the masking tape and pressing it together.

Similarly, masking was also applied to the silver metallic first color coating 15 on the sides of the body.

A second color base coat red metallic paint containing red pigment and aluminum powder is applied to the masked body as described above to a dry film thickness of 15μ, and the resulting paint film does not dry. A clear paint was applied to the surface as it was to give a dry film thickness of 25 μm, and the film was baked at 140° C. for 18 minutes to obtain a red metallic second color paint film 16.

The masking tape was then peeled off along with the masking paper and the heat-resistant adhesive tape.

In the two-tone coating obtained, no streaks due to residual adhesive were observed on the black first color coating 14 on the front panel and the silver metallic first color coating 15 on the lower side parts. Nakatsuta.

Comparative Example Two-tone coating was applied in the same manner as in the example except that the masking tape used in the example with an adhesive layer provided on the entire surface was used as the masking tape.

In the resulting two-tone coating, streaks due to residual adhesive were observed on the black first color coating 14 on the front panel and the silver metallic first color coating 15 on the lower side surfaces.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one aspect of two-tone painting, FIG. 2 is a cross-sectional view showing a masking method in two-tone painting shown in FIG. 1, and FIG. 3 is a cross-sectional view of a conventional masking tape. Figure 4 is a cross-sectional view showing how the adhesive protrudes from the sides when conventional masking tape is pressed onto the first color paint, and Figure 5 is two-tone painting using conventional masking tape. Fig. 6 is a cross-sectional view showing another aspect of two-tone coating; Fig. 7 is a cross-sectional view showing one embodiment of the masking tape used in the present invention; FIG. 8 is a cross-sectional view showing one embodiment of the masking method of the present invention, and FIG. 9 is a sketch showing the body of a wagon type automobile to which two-tone painting was applied in the example. (Main symbols in the drawing), 1: Body, 2, 8: 1st
Painting of color, 3, 9: Painting of second color, 11: Masking tape, 11a: Tape base material, 11b:
Adhesive layer.

Claims (1)

[Claims] 1. Masking tape that does not have an adhesive layer on the opposite end of the edge corresponding to the boundary line between the two paints is used as a masking tape used to form a boundary between two-tone paints of different paint colors. A masking method for two-tone painting characterized by the following.